Question

How is the moment of inertia a tensor?

Answer 1

Inertia:

1. Unless acted upon by an external force, the matter remains at rest or in uniform motion along the same straight path.

Tensor

1. A tensor can be defined at a single point or a collection of isolated points in space (or space-time), or over a continuous set of points.
2. The members of the tensor in the latter instance are functions of the position, forming a tensor field.
3. A tensor can be made up of only one integer, which is known as a tensor of order zero or simply a scalar.
4. Moment of Inertia (I) is a tensor quantity because it possesses both magnitude and direction but does not obey vector algebra; as a result, it behaves both like a vector and like a scalar, thus earning the name tensor quantity.